Letterbook Docs
Create a conversation
Open a new customer conversation in Letterbook from an external system.
Last updated June 3, 2026
What this guide covers
Create a conversation when a support request starts outside a connected inbox, such as an app form, web form, or internal system.
Endpoint
POST /api/webhooks/conversations
Request fields
customer_emailcustomer_namesubjectmessagemessage_htmlpriorityexternal_id
Response fields
iddisplay_idstatusurl